Police-signal system



March 24, 1931. c, BAUER 1,797,281

POLICE SIGNAL SYSTEM Filed July 13, 1928 2 Sheets-Sheet l PKC. Curve (Su I GP PF 7 31718 L13? Relay 60 Y6. L'upe 28* Mastr 61* 67 Sigpal Swilb 6'2 March 24, 1931.

G. F. C. BAUER POLICE SIGNAL Filed July 13,

1928 2 Sheets-Sheet 2 j oc Li 9e CflcLLi I 6 o Wager Cal I I Relay .77 -55 =2 0 :cers Report swi W1 c. 63 9%, @WWW Gr m v.1 n15 to be thrown the other way for a short time to give an audible signal and all would have to be again thrown back to give a continued visual signal. The individual manipulation of this number of keys to give the desired signals necessarily took time, and particular- 1y if several ofiicers were being called, some of whom responded more promptly than oth ers, created a great deal of confusion in'manipulatingthe signal keys and other devices of the switchboard. V

The present invention proposes a'police sig' nal system in which the substation signal keys have only one operative "position, i.-'e., each signal key can be moved from its inoperative position to one operative position in which operative position the corresponding substation circuit is set upfor substaton sign al operation. By these keys asmany substation circuits may beset up for signal op eration as may be necessary, but the signal keys are nonselective as to the type of substationxsignal actuated. In the normal condition of the substation circuits, the source ofenergy for signaloperation is arranged to supply energy for visual signal operation. It therefore follows that in the normal condition of the substation circuits, the setting of the signal keys will effect anoperationof the visualsignals of the corresponding substations. j

Y Fornthe purpose ofjactuating the audible substation signals a master signal switch, is

35: included in the signal energy supply circuit,

this master signal switch-being common to all of the substation circuits and being so arranged that the substation-signal circuits set upv by the operation of theindividual signal keys are changed was to supply energy to the audible signalonly. I

By this means, the proper signal keys are setto signal the desired boxes or substations anda normal visual signal is effected. and .to then effect .an audiblesignal at-each of these boxes, the switchboard'operator presses the master signal switch which cuts off the visual signals and places the audible signals in circuit with the set keys. After a few blasts on the audible signal, the master signal switch is released and the visual signals auto matically continued until the 'oficer responds to the call and the signal keys are thrown back to their inoperative position. I

' The provision of this master signal switch therefore" provides a very simple and direct method of changing from visual signals to audible signals on any group .or combination substation circuits that may be'placedin operation at any time, and a1 savingin time and confusion is eflected in manipulating the substation signals.

" r further object is to'provide such a fcuit which contains a lllof the essential elemass "or 'a police signalsystempwhich is shown in Fig. 2-are connected by theusual telephone lines each comprising a tip side 5 anda ringside 6. 'At the police box the usualv telephone receiver7, hook switch8 and trans mitter 9 are in circuit with'the tip and ring sides of the line circuit, these elements being arranged inthe usual manner so that when the receiver 7 is removed from the hook switch 8, an electrical circuit is established through the tip side ofthe circuit, receiver, transmitter and ring side of the line circuit.-

At the centralstation'the tip side 5 of the line circuit is'connected to one armature 10 of a line relay 11,this armature 'normally or in the deenergized condition of the line relay 11 being held in contact with a wire '12 which connects with thetip spring contact 13 of the line jack 14;. This line jaokwire 12 is also connected by a wire 15 with a line relayIG, the, other terminal of this line relay 16 being connected with a wire 17 the other end'of which connects by a wire 18 with a battery and a ground G. i 1

The ring sided ofthe line is connected with the other armature 19 of the line relay 11, this armature normally or in the deenergizedcondition of the relay 11 beingheld in contact with a wire 20 which connects with the ring spring contact 21 ofthe line jack 14. This line jack wire 20 also is connected by a wire 7 22 with the movable wagon call release 'contact"'23 of the signal key 24'. This movable wagon call release contact 23 normally contacts With a fixed wagon call release contact 25 which is connected by aw-ire 26 with a line relay 27. Theother terminal ofthis .wire 29, this wire 29 being connected by a Wire 30 with the battery '13. 1

- One of the armatures 31; of the relay 16 is connected by a wire 32 with the battery wires 29-and 30 and upon energization of this relay '16, this armature 31 is moved into contact with a wire 33. This wire 33 is connected with one of the fixed contacts 342 of the line jack, this fixed contact normally, or in the -unplugged-condition of the jack, engaging the spring contact 35 thereof. This spring contact 35 is connected byawire 36 with a white line lamp 37 the: other terminal of which is grounded. Thiswhiteline'lamp 37 is closely linerelay 27 is connected by a wire 28 with a".

team

7 5 associated with theline jack 14 on the switchboard.

Vvhenapoliceman at the police'box or substation'}wishes .totalk with the switch board'operator, he lifts the receiver'7at the-- boxu "This establishes a circuit through batl teryB, Wires 30,29 and 28,-line relay 27, wire- 7 26, fixed wagon call'release contact 25, n1ov-'- able wagon call release contact23, wires 22 1 and 20, armature 19 ofthe line relay 11', ring side GfQf-linecircuit, transmitter. 9, receiver" 7, hook switch 8, tip side of circuit, annature :wir'es'12 andlo, line relay 16, wires 17"andf-V18to the grounded, side of the bat-V teryBr' vv Y s. =Upon the energization of the line relay 16; its armature'31 is pulled up and a circuit is established 'thr'oughbattery 13, wires 30,

29 and 32, armature 31 of relay 16, wire 33, fixed'contact 34 of the line jack, spring contact 35, wire 36, white line lamp 37 to ground.

Upon-observing the illumination of the I white line-lamp 37, the switchboard opera- 1 torplugs in thelin'e j ack 14. This separates the line jack ring and tip springs 13 and '12 andat thesarne time' noves the movable contactoutof engagement with-the fixed contact34; so 'as' to'bre'ak the circuit through the white line :lamp 3'? :At the same time the plugging into. the line j ack places the opera. e tors set (not shown) in circuit with the tip" and ring spring contacts 13 and 210i the line: f jack, and as the 'tip i spring contact 13 is di-p rectly in circuit witli theltip side 5c of the circuit through wire 12, armature: '10 an'd'tip;

side i5and as the ring spring contact2l is directly in circuit with the ringside 6 of the circuit through wire 20;:arn'1atureIQandring side 6, the operators setis placed in circuit by. plugging in the line jack 14' andac tele phone circuit-x is established between the switchboard operator-l d 1 x sub; station; I r .7 l

. To illuminate the 'white linelainp 37 when I the ofiicer at'the substation hangs'up' his re ceiver and thereby provlde a supervisory s1gnal onthe substatlon circult when used as a conventional telephone circuit in inaking suh station to substation calls through the switchboard,-tlie ar1nature'31of the linerelay16 in the deenergiz'ed condition of ithejf-relayyconf. tacts with a wire 1O1-,' this wire being con;

nected with a supervisory springcontact 1Q2 in" the line jack. hen the [linelqack' is plugged in, the movable springicontact 35 is heldin engagement with the'superyisor y contact '102,""but as long; as the telephone. an

cuit-is in use,th'e armature 31 of the relay :16.

is pulled up so as"toirender,thisflcircuitinope rative. When lthef parties hangup, howeverrthe relay lfilisdeenergized as'deser bed and the armaturejfiircontacts with the; wire I 101 thereby closing a circuitwthrough I battery;

B, wires 29 and-.32, armature 31 wire 101;

I supervisory contact, 102, movable eontaaise,

wire 36, what-asa 37 ag ound; [The switchboard operator then. knows that the parties have hungup and removes thefplug from vthe -line jacksof both circuits.

;Whenthe switchboard" operator desires to call the oflicer' on dutytoloneiof hisboxes, 'hesignals the otficer-.:-who responds tothe call in the manner. described under the caption Operation ot the signal circuit.

I f. f fett rol w dgonjcall; I f

:Wheifthbficer atthe be: was OI aaa can fort p g n, he Pulls flown I on the hook'ota wagon'call switch38"which effects a wagon call indication at the switchboard and the box,.this 'signallingindication I being maintained'untilthe; switchboard oper- The wagon call switch 38includes a central contact 39 and twocontacts LO-and 41', the central contact 39 norinally engaging the contact l1 andfbeing movable out of engageinentwith this contact 41 andinto engagement with the contact 40upon pulling the hook to Inakea wagon call signal. The centralcontact 39 is directlyconnectedwiththe ring side 6 of the line circuit and the contact 40i's congator releases the circuit nioying thesignal v key 2411p to wagoncall releaseposition. 1 I

nected by a wire 43 with a-holding relay e45 I the othereterininalof whichis'connected to a v grounded wire 45. a One armature 4601f the 7 holding relay llj'is connected bya wireefiwith the ringside fiiof the circuitand uponjbeing Immedup engages thf Wire -48 connected with thewire'e3, v I a tact ll otthe wagon call switch; Uponfble: ing pulled up, tl 1 e armature 4 9- contacts'-with 5 of the line. I 7

throughthe battery B, wires 29fand 28, line, relay27, wirel26, closed wagon call contacts 25,:and123'of thej signal key 24, Wires 22 and" .7

I tr al; contactl; 39 and contact'tO of the wagon callf'switch38, iwire l3, holding'relay H, and g wire45rto ground; QTheenergization of the. I I

20,. arinature"f 19,- .ring side 6 of the line, cen-' holding relay-44 pulls up its armature-lfiand 14H, g 109 Theother armature49 of the holdingr'elay, 1 44; is connected by a wire-50 with a wagon call I V buzzer 51, the other terminal of this buzzer j '5 being connected by a wire 5i2 withthe con a- Wire 53 which is connected withtheJtip side a When the offiCer-pulls thewagoncallswitch I 38 to put'in a wagon call, the contacts39 and 11o leOfare closed and: aw-circuitisestablished lease of the'wago n call switch. 38, a circuit is v established throughithei ring-sidebof th l in 1., Q central contact -Li g jtand contact {41 of; .the

wagon call switch,wire52,-buzzer-51, wire 50,

armature 49, and wire 53 to the tip side of.

the-line; I a i .7 r Before the wagoncallswltch is released to its normal inoperative position, a circuit'has beencstablished over ring side of line to ground which is practically identical with that established by sending an ofiicersreport. NVhen the wagon call switch is released a circuit is then established which is practically identical with that of a telephone call except 1 that the line circuit over tip and ring is held closed through wagon call buzzer51. V i

' By this means a buzzing circuit is estab lished across the telephone line and the. white line lamp 37 atthe switchboard will be illuminated as described in connection with the The operator thereupon V telephone I circuit. plugs into the line ack 14 and receives a buzzing indication in his set which'indicates that a wagon call is being made. After noting the wagon call, the sw tchboard operator moves the signal key 24 up, which movement breaks the contact between the wagon call contacts 23 and 25 and thereby breaks the circuit between the battery B and the ring side 6 of the line. This cutting off of the battery Breleases the holding relay 44 and all parts of the wagon call and telephone circuits are restored tonormal, 'By this circuit, the wagon call-buzzing indication is main tained both at the box and at the switchboard until the switchboard operator positively re leases the circuit. The oflicer at the box by-a wire with the wire 50. A

Q Q S hat his wagoncall has been received i v Oyfiers report circuit To insure that the olficerfis attending. to h sdutles, the'oiiicer is required to report at lntervals, a printed record of such report be ing made at the central station preferably by' means of a recorder such as described in my copending application, Serial No. 287,617, filed June 22, l928,for a recording apparatus.

This record is made by the ofiice'r at the box closing an ofticers report switch 54' one terminal of which is con'nect'ed with the wire 45 and the other terminal of which is connected At the switchboard,'the other of the line relay 16 is connected byawire 57' with the batteryivire 32 and'whenthelline relay 16isdeenergized, this armature 561conta-cts with a wire 58 connected with one of the armatures 59 01" the line relay 27. lVh e'n this armature 59 pulls up, it contacts with a;-

w-ire 60 which connects by neansof a wire 61 with a holding relay 62. "The other termin al of the holding relay 62is connected by 'a wire 63 with the recordingapparatus- (not'-- shown); Theiarrnature 64of'thi's holding liner-relay 62 is connected by): a wire 65 with the'battery wire 28 and is pulled up into con;

rrnature 356.

tact with the wire .60 when the holding linerelay 62 is eneri'igizedf When the o oer at the box closes the of ficers report switch 54, a circuit is established through battery B, wires 30, 29 and 28, line relay 27, wire 26, wagon call release contacts '25 and 23 of the signal key 24,-wires 22 and 20, armature 19, ring side 6 of line, central battery B wires 30, 29, 28 and 65, armature 64,

wires 60 and61, holding line relay 62 and wire 63 to the recording apparatus. 'In this manner the recording circuit is held until therecordermakes a record of thetimeand the box recording and breaks the recording circuit and'relcases the holding line relay 62 as described in my said copending application for recording apparatus, Serial No. 287 617, filed June 22', 1928. By this means the oihcer at the box merely hasto momentarily ciose the-ofiicers report switch and the circuit is automatically maintained until a propor printed record is made.

Each time. a call is put'in for a patrol wagon through the operation of the wagon call switch 38, the recording apparatus associated with the wire 63 at the switchboard is operated to make a printed record of a report from the box called from and the time thereof for the purpose of having a permanent record of such; wagon calls together with the regular reports. The circuit through which this report is made is as follows:

-' Upon pullingthe' hook. on the wagon call switch 38, the central contact 39 thereof is moved into engagement with the contact 40 thereof, and a circuit is established through battery B, wires 29 and 28, line relay 27, wire 26, closed wagon call contacts 25 and 23 of the-signal'key 24, wires 22'and 20, armature 19,-r1ng slde 6 of the l ne, centralcontact 39 and contact 40 of the wagoncall switch 38, wire 43, .holding relay 44, and wire 45 to ground, as described i-n connect-ion"withthe wagon-call circuit. The energization of the line relay 27, as previously'described, pulls up its armature 59 and thereby establishes a circuitthrough battery B, wires 30, 29, 32 and 57-, armaturel56, wirej58,"armature 59, wires 60 and 61, holding relay .62 and wire 63 to I the recording apparatusz The holding relay 62 .thenlholds this circuit -un t-i1 a printed" IGCOI'd 'Ji S made by the recording apparatus and the circuitbroken thereby,.-as;described.

instructions;

These signals are conne'cted by a wire 68 which connects with" one terminal of each signal and is also connected by'a wire 69 with the-tip side of the'line. The other terminal'of thevisual signal 67? is: connected by a wire 70 withgrouni and' the other terminal of the audible signal er'lio'rn 66 is connected by a wire 71 withithe' ringside 6 oftheline,

a condenser ,72 being preferably'arra'nged in this line. this means, the audible signal ently appear. r g V a Y 7 Each of the audible-and visual signals is adaptedito intermittently actuated and for this purpose a motor'operated fiasher 73' former contact78; y 7 y The audible and visual signals of e-ch'bo r circuit'is metallican'd the visual signal circuit is grounded thereby permitting of theiralternate independent operation as will presis'vmounted on'the switchboardand by the engagement of a salientplate 74011 the rotor, intermittently moves a movable battery contact 7 5 and a movable transformercontact 7 into engagement, respectively, with a stat one arv batterv contact? 7 and a station'arytransare individuallycontrolled by throwing down the signal key 24 which holds its signalling position until manually restored. v The throwing down of this key establishes a circuit through the red line lamp'SO "on; the

' switchboard, the flasher 7,3, .andthe audible or visual'signal depending on the position of the master signal switch 81 which controls a the wire86.

" Thesignals are actuated from a transformer Tfthe prim'ary'coil 92 oft-which is con switchboard; v 4 g 7 Q The stationary battery flasher contact 77 the signallingfeitect of'allset keys'on the is connected with the battery wire 33'and the 7 corresponding movable contact 7 5 is connected by a wire 82 with the movable signal contact 830i thesignal key 24. The fixed signal contact 84is'connected by a wire 85 with the red line" lampBO on the switchboard and the other terminal of this red line lamp is connected wires 86 W187 with the other armature 88 of the line relay 27. This armature; 88 is connected by a wire 89 with a grounded wire 90. 'To' siinultaneously energizefitheline relay 11, as presently described, one terminalofthis relay is connected by a wire 91 with the fixed signal contact 84 while "he other terminal this rel'ayconnects with nected tov alternating currentsupply wires 93 and 9e and the secondary coil 95-of which is connected-by a Wire 196 with the fixed flasher contact 78, whileethe other terminal of this secondary coil 95 isconnected with a wire. 97, whi'chwire 97 is adapted. to contact with the armaturell) of the line relay ll when.

this relay 1s energ zed. 7

. lhehmster signaljswitch 81 comprises a manually operable contact 98 which isnormallyheld in contact'with thegroundedwire andgismanually movable into contactw-ith a wire 99 ;,;lhe wire/99 E engagedby the are" mature 19 of the line relay ll when the line; Zrelay ll is energized. ;The movable contact 98- of the in aster signal switch is I connected by a wire 100 with the movable transformer Ifiasher contact76 of'the flasher 73. v a 4 V 1 Operation, of thsz'gmtl The switchboard operator throwsthe signalkey24 down which closes the signal. contacts 83 and 84;. ,This downward position. is automatically held until the signal key is manually'reset: 1 7 I v Thisfmovement of f'th e: signal rkeynestablishes a circuit through batteryB, wire 30,

and stationary-"andmovable battery con tacts: 77 and 7510f theflasher.73,'wir=e 82, i

movableandIfixed signal contacts 83 and 84 ofthe signalkey' 24, wire 85, red line lamp 80, wires '86and 87,; armature 88 andiwires 89zand 90, to grounda The. red line. lamp 8,0

ontheiswitchboard isgtherehy 'flashed on and off to indicate that the corresponding signal *key isset to give-, awisualor-audible signal at the correspondin' 'box or substation. a At the same time inerelay No.11 is-energized to pull up its: arniat'ures and, place the transformer Tin circuit withthe flasher and the visual. or, audible signal. This relay 11 is 'energized through the followingcircuit:

battery .B, wire 30, stationary andvmovable batterycontacts 77 and7-5 ofthe flasher 7 3,

wire 82, movable and fixed signal contacts83 l and 84 of the signal key 24,.wire 91, line. relay "11; wires '86. and 87, armature .88, and

wires 89 and 90 to ground. The line relay 11 is therefore energized and pulls its armatures 19 and 10 into contact,- respectively withithce wires 99 and 97. i 1 V Assuming that the master signal switch 81 is in its normal position shown, in whichiits movable contact 98 is in engagement with the rounded wire 90, thei visual signal will be ashed onand 011' through the followingcircuit: i

, Ground Gawire 90, mastersignal switch contact98, wire 100, movable and fixed trans former flasher contacts 76 and' 78', wire 96,

secondary coil otthe transformer, wire 97,-

arinature 10 of energized relay 11, tip side. 5

of line, wires 69 and 68, visual signal light. at

box and wire-70 to'ground. Through this V grounded circuit an intermittent operation of thevisual signal light67 at the boxi will be maintaineithe circuitbemg made and transformer, flasher. and audible signal as 7 follows Secondary coil 95 .of the transformer, wire 97, armature 10 of line'relay 11, tipside 5 of 'line,'wires 69 and 68, audible signal horn 66, wire 71 and condenser 7 2, ring side 6 of line. armature 19 or, energized line relay 11, wire 99, master signal switch contact 98, wire 100, movable and stationary condenser flasher contacts 76 and 78, and wire 96 to the other terminal of the secondary coil 95. By this means as long as the master signal switch contact 98 is held manually in engagement with-the wire 99, a metallic circuit through the audible signal 66 is maintained and the same alternately. actuated by themaking and breaking of the circuit by the'flasher'. After several blasts,- the switchboard operator releases Ithe master signal 'switch'81and the grounded circuit through the visual signal 67 is maintained until; the officer responds to the signal. ff": 7

The transformerjT, flasher 73"and master signal switch81 are common to all of the line circuits and hence th eoperation of the master signal switch to give either an audiblefofa visual signal affe ctsall of the signal circuits, the signal keys2 l of which are set to signalling position. this'means in calling a number of boxes, the signal keys of these boxes are set to signallingposition, and after being set the master signal switch is held down for a shortinterval to give a few audible blasts .on the horn 66, and then the master signal switchisre'leased thereby continuing the visualsignalluntil the oflicer or oflicers being called respond. 7 In this manner the time to change the signalling circuits from visual'signalling circuits to audible'signal ling circuitsand vice versa is materially reduced as compared with circuits 1n WlUCll this change is effected through the indlvrdual signal keys. v When the SIlbStHtlOIYOlICLIlt 1s lnnormal or inoperative condition, the armatures 19' and 10 ofthe line relay 11 provide a com.- plete telephone path from the substation through relays 16 and 27, line jack 1 1 and this instant, would not be able to signal the central station uponremoving the receiver from the hook switch .8, since during this sig- Vnalling interval the signal energy would pass through the substation telephone receiver 7 and transmitter 9. The telephone receiver 7 does not include a permanent magnet but is of the electro-magnetic type and therefore'the alternating current used for signal operationcauses no damage to thereceiver when it is lifted during a signalling conditionof the circuit. i

The signal circuit is intermittently energized' through the flasher 7 3, and as soon as the flasher contacts 77 and break, the relay 11 is released andthe a'rmatures 19 andlO thereof move into engagement with the wires 20 and 12 and thereby restores the telephone circuit or couples the switchboard telephone equipment with the substation circuit and the fact that the oflicer has lifted the receiver is noted by the illumination of the white line 37 at the switchboard as described unonly when one side of its winding is connected to ground through wires 86 and 87, armature 88, and wires 89-and 90 to ground. When a telephone call. circuit is established by lifting the receiverfrom the hook at the substation, the relay 27. becomes operative thereby breaking the connection between wire 87 and armature 88 thereby. disconnecting the ground fromrelay llat'this point. This prevents further operation of relay 11.

Thecondenser 72 must be of relatively large capacity sothat the audible signal 66 can be operated 'with current necessary for its proper operation. This condenser is essential in the substation circuit to prevent battery current flowing over the substation circuit from flowing through the audible signal 66 under normal conditions. This condenser carries a relatively high chargewhen the signal energy is disconnected at the. contacts 76 and 78 of the flasher 73. Therefore when the relay 11 restores the substation circuit to its normal connection with the switchboard telephone equipment after each signal interval, a path is provided through the relays 60 and'27over which the condenser 72 would discharge in the absence of provision to prevent it. This discharge would cause a disagreeable reaction in the substation circuit, that is, a momentary flashing of the white line lamp 37 through the momentary closing ofv the armature 31 of the line relay 16 and might also cause the recorder to operate through the momentary operation of 1 the relay 27. 7

Togprevent either of'these from occurring,"

' a means isprovided fordischarging the condensers 72 ofall operative substation circuits through a groundedicontact 79 mounted in the-rotor of the flasher 73. To clearly understand how this'ocjcurs; I" givethe following 1 description of the flasher construction:

f The mechanicaldesign of the flasher 73 is such thatthe'battery contacts Y5' and77 close beforethe transformer contacts. 76 and 78are closed This permits all of thesignal control' relays 11 that inay be in use to come into operation before the transformer flasher contacts-76and 78 are closed. In reverse order, the; transformer flasher contacts 76 and 78 break the transformer circuit before the-batc tery flasher contacts? 5 and 77'break the-bat 'fiash er' contact 76- which iscon mon to the ring side'offall substation cirouitswhich are ,in-a signal operativepositiomdrops from the salient plate 74 of the flasher 73 and engages thergrounded contact 79 on the rotor of the flasher This providesa discharge circuit for the condenser 7 Qbefore the relay 511; has an opportunity to restore the sribsta 'tioir circuitt'o' its normal inoperative positi'on. This'discharg'e'circuit is as follows'z providing a discharge'circuit.

3 Flasher ground, contact 7 9, flasher contact 76, wire 100, master signal switch spring 98, Wire 99, armature 19 of line relay 11, ring side-6 offline, condenser 72,wire -71, audible signal 66, Wire 68, visual'signal 67, and wire to groundi As will be noted in this description, this-circuit will be completed only'whenthe master signal switch 81 is in 'aposition for operatingthe audible signals at thesubstamons. Dur ng such periods when the master signal switch 81 is in normal position shown in Fig. 1 and the visual signals 67 are operated, there is no necessity of Another important reason why the flasher 73 is so designed and constructed to'cause the battery flasher contacts 75 and 77 to close be forethe transformer flasher contacts 76 and 78 close and also thetr'ansformer flasher'contacts to open before'the battery 'flasher contacts open is to establishclosed circuits through thecont'acts on line relay 11 and over thegsubstation circuit and also to disconnect thesignal energy from the substation'circuits over the coritactsof'relayll before these con tactsbreak to prevent anyarcing from o'c-' curring on these contacts'on substation circuits.""- r 7 As awhole this signal systemperforms all necessary functions of a police signal system, it is simple to operateanol not liable to lead to V erroneous signals, and provides simple *ci'r ec uit arrangements' which will not easily get I'cl'aimas niy'invention.: v V v v 1. In combination with, i s telephone system,

out of order and can be readilyrepaired.

a police signal system, coinprisingfa central staton, aplurahtyof substations and circuits connecting said central station with said sub-* stat on's, a power source associated wlth said substat on circuits, avisua1 and an audible "signal device at eachjof. said substations, and a master.Zswitclr atqsaid central station. and associated Withsaid power source and allof said substation circuits,= said master signalswitch in ione position being adaptedto sup- I ply energy from: said vpower source for the operation ofgany-group of sa dvisual signal devicesand inanother position being adapted to supply -I energy" for the operation of the corresponding audible signal devices.

, 2; Incombination with a telephone system, a police signal system, comprising a central station, aip'lurality of substations and circuits connecting said central station with said substationsi a power source associated with said substationcircuits, a visual and an audible signal device'at each of saidsubstations, each of one type of said signal devices beingcon nested across the respective circuit andv each of'the other type of said-signal devices being grounded," and master signal s'witchatsaid central station andicoinmon to all of sa d substation circuitsand saidpower source, said master signal switch in: one position being groundedan d being adapted to supply energy from said power source to any of sai grounded signal devices asa group and said master signal switch in another position being connected across'sai'd substation circuits and said power source and being adapted to supply energy to thecorresponding other type of signal devicesasa group. I

3. In combination' with a telephone system.

a; police signal system, comprising a central statioma plurality ofsubstations and circuits r r connecting said central station with saidsub stations, a powersource associated with said gizeone ofsaid signals of itsrespective circuit, an audiblesignalfdevice at each of said substation circuits," a grounded visual signalv substations and'conne'cted across the substa- 'all' of said substation circuits and said power source, sa d master'signal switch inone position being fgroun'dedand being adapted to supply energy, from said power sourceto any ofsaid grounded visual signal devices .as a group'andsa d master slgnal switchin another position being connected across said substation circuits and being adapted to sup- 7 tion with said substations, a visual signal de vice at each of. said substationsand having one terminal-connected withone line of the substation circuitand'its otherterminal being grounded, a signal switch associated with each of said substation circuits and operating, when closed, to energize one of said signals of its respective circuit, an audible signal device'ateach of said substations and being connected across the substation circuit, a common source of energy in said one line of each substation circuit, a signal switch associated with eachof said substation circuits and operating, when closed, to energize one of said signals of its respective circuit, and a master signal switch atsaid central station and'common to all of said substation circuits from said power source, said master signal switch in its normal position grounding said one line'of each substation circuits andthereby vices as a group.

5. In combination with a telephone sy tem, a police signal system, comprising a central station, a plurality of substations and circuits connecting said central station with said substations, a power source associated with said substation circuit-s, a visual and an audible signal device at each of said substations, means at said central station for selectively setting up individually any number of nal devices and master means for changing said set visual signal circuits to audible signal circuits as a group. f

6. In combination witha telephone system, a police signal system, comprising a central station, a. plurality of substations, and substa tion. circuits connecting said central station with said substations, a power source associated with said substation circuits, a visual and an audible signal device ateach of said substations, means at the central station for individually setting up any number of substation signal circuits andsupplying energy to operate said visual signal devices, and a master switch associated with said substation circuits and adapted to supply energy to the audible signal devices of said set signal circuits asa group; I

7. In combination with a telephone system, a police signal system, a central station,

a plurality of substations, and circuits connecting said central station with said substations, a power source associated with said substation circuits, means at said central station for setting up any number of substation signal circuits, a grounded visual signal device at each substation and connected with the corresponding substation circuit, an audible signal device at each substation and connected across the corresponding substation circuit, an individual switch for setting up each circuit and energizing one of the sig- 1 nals thereof and a master. signal switch at said central station and common to all of said substation circuits, said master signal switch in one position being grounded and being adapted to supply energy to all the grounded visual signal devices on the set signal circuits and in another position being connected across said substation circuits and being adapted to suply energy to the audible-sig- 112118011 the set signal circuits as a group.

8. In combination with a telephone system, a police signal system, a central station,

a plurality ofsubstationsand substation circuits connecting said central station with each of said substations, means at said central station for setting up and energizing any number of substation signal circuits, a visual signal device at each substation and having one terminal connected with one line'of the substation circuit and'its other terminal being grounded, an audible signal device at each substation and being connected across the substation circuit, a common source of energy in'said one line of each substation circuit, and a master signal switch at said central station and common to all of said substation circuits, said master signal switch in one position grounding said .one line of each set substation circuit and thereby energizing the corresponding visual signal devices as a group and said master signal switch in another position being connected across each of said substation circuits and energizing the audible signal devices on the set substation circuits as a group.

9. In combination with a' telephone system, a police signal system, a central station, a plurality of substations and substation circuits connecting said central stationwith each of said substations, each of said circuits including a primary switchboard circuit having a relay and a switch for setting up said primary circuit and energizing said relay and a secondary circuit rendered operative by the energization of said relay and each secondary circuit including a grounded visual substation signal device connected with one side of said secondary circuit, an audible substation signal device connected across said secondary circuit and, a master signal switch and source of energy common to all of said secondary circuits, said master signal switch being adapted in one position to be connected across said secondary circuits and energize theaudible substation signal devices station of allset circuits and in another position to ground one side of each of said secondary circuits and energize the visual substation signal devices of all set circuits.

- 10. Incombination with a telephone system, a police signal system, a central station, a plurality of substations and subcircuits connecting f said central station with each of said v each of. said circuits including a primary T switchboard circuit including a relay having two armatures and a switch for setting up said primary circuit and energizing said relay, and a secondary circuit having a tip side in circuit with one of said armatures and a ring side in circuit with the other armature, a grounded visual substation signal device connected with said tip side, an audible substation signal device connected across said ring and tip sidesand a master'signal switch and source of energy common to all of said secondary circuits, said master sig- ,nal switch in one position being adapted to establish a circuit across said ring and tip sides on all set substation circuits and there- 7 by energize the audible substation signal detion to establish a circuit through said vices/onall set circuits and in another'posiv grounded visual signals on all set circuits.

"11. In combination with a telephone system, a police signal system, a central station, a plurality of substations and circuits connecting said central station with each of said substations, each of said .circuitsincluding a primary switchboard circuit comprising a relay having two armatures, a battery and aswitchfor setting up the primary circuit and energizing said relay and a secondary circuit having a tip SlClG lIl circuit with one of said'arinatures and a ring side in circuit .with the other armature, a groundedvisual V substation signal device connected with said tipvside, anraudible substationsignal device connected across said ring and tip sides, a source of electrical energy in said tip side,

' and a master signal switch common to all of said secondary circuits and adapted in one position to establish a circuit across said ring and tip sides on all set circuits and energize the audible substation signal devices thereof 7 and in another position to ground said tip sides on all set circuits and establish a circuit through all visual signal devices thereof, a

said master signal switch being normally held in the position in which it grounds the "tip sides and energizes the visual signal devices.

In testimony whereof I aflix my signature.

" GUSTAV F. C. BAUER.

substations, v 

